1. Reactivity characterization of bromoacetyl derivatized polyribosylribitol polysaccharide in Haemophilus influenzae type b for PedvaxHIB® by NMR spectroscopy.
- Author
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Rustandi, Richard R. and Xu, Qiuwei
- Subjects
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HAEMOPHILUS influenzae , *NUCLEAR magnetic resonance spectroscopy , *VACCINE effectiveness , *NEISSERIA meningitidis , *SMALL molecules , *POLYSACCHARIDES , *IMIDAZOLES , *THIOLS - Abstract
• NMR spectroscopy is used to characterize reactivity in bromoacetyl-dPRP. • Reaction with 2-mercapto imidazole provides proton NMR assignments in BrAc-dPRP. • Bromine loss from BrAc-dPRP before conjugation can be monitored using NMR. PedvaxHIB® is a highly purified capsular polysaccharide (polyribosylribitol phosphate or PRP) of Haemophilus influenzae type b (Hib) that is covalently linked to an outer membrane protein complex (OMPC) of Neisseria meningitidis pediatric vaccine. This Hib protein conjugate vaccine is very effective in protecting infants from invasive gram-negative bacterium Hib. Before conjugation of PRP to OMPC, PRP is first derivatized with butadiamine and bromoacetyl group which reacts with thiolated OMPC. This report describes an NMR method to analyze the reactivity of bromoacetyl group in derivatized PRP (BrAc-derivatized PRP) toward small molecule thiol group, 2-mercapto imidazole (MI) which is used as a surrogate for thiolated OMPC. Reaction with MI helped identify observable amide protons in BrAc-derivatized PRP according to presence or absence of bromine. Furthermore, the new method can be used to monitor the percent of bromoacetylation during manufacturing and potentially a stability indicating assay for loss of bromine in BrAc-derivatized PRP. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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